51307565767261 has 2 divisors, whose sum is σ = 51307565767262. Its totient is φ = 51307565767260.

The previous prime is 51307565767181. The next prime is 51307565767309. The reversal of 51307565767261 is 16276756570315.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25697701104100 + 25609864663161 = 5069290^2 + 5060619^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51307565767261 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51307565767261.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51307565767561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25653782883630 + 25653782883631.

It is an arithmetic number, because the mean of its divisors is an integer number (25653782883631).

Almost surely, 2^{51307565767261} is an apocalyptic number.

It is an amenable number.

51307565767261 is a deficient number, since it is larger than the sum of its proper divisors (1).

51307565767261 is an equidigital number, since it uses as much as digits as its factorization.

51307565767261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 55566000, while the sum is 61.

The spelling of 51307565767261 in words is "fifty-one trillion, three hundred seven billion, five hundred sixty-five million, seven hundred sixty-seven thousand, two hundred sixty-one".